Past sea-level suggests troubling future

  • Thread starter Thread starter Ivan Seeking
  • Start date Start date
  • Tags Tags
    Future
Click For Summary

Discussion Overview

The discussion centers on the implications of past sea-level rise for future projections, particularly along the U.S. Gulf Coast. Participants explore various aspects of sea-level changes, their causes, and the potential consequences for coastal regions, incorporating both geological research and differing viewpoints on climate change impacts.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants reference research indicating that historical sea-level rises of about 50 centimeters per century have significantly altered coastlines, suggesting that similar increases could occur this century.
  • Others argue that while sea levels are rising, evidence from certain regions indicates minimal changes, with some reports suggesting an average rise of only 0.3 mm per year, which is less than some predictions.
  • One participant highlights the role of water salinity and ocean currents in the climate system, suggesting that changes in salinity due to ice melting could disrupt these currents and lead to further climatic shifts.
  • Concerns are raised about the accuracy of claims regarding sea-level changes, with some asserting that land shifts may be contributing to perceived changes in sea levels rather than actual rises.
  • There is a discussion about the credentials of sources cited in the debate, with some participants expressing skepticism about the authority of certain individuals and the validity of their claims.
  • One participant emphasizes the specific situation in Louisiana, noting that land loss due to levees and rising sea levels poses a significant threat to New Orleans.

Areas of Agreement / Disagreement

Participants express a range of views on the causes and implications of sea-level rise, with no consensus reached on the accuracy of specific claims or the overall trajectory of sea levels. Disagreement exists regarding the interpretation of data and the significance of various factors influencing sea levels.

Contextual Notes

Some claims rely on specific studies and reports that may not be universally accepted, and there are indications of shifting land masses that complicate the understanding of sea-level changes. The discussion reflects a mix of scientific inquiry and skepticism regarding the interpretations of data.

Ivan Seeking
Staff Emeritus
Science Advisor
Gold Member
Messages
8,252
Reaction score
2,664
Look at past sea-level rise points to troubling future
Rice U. geologists probe impact of rising seas along US Gulf Coast

New research presented at this week's annual meeting of the Geological Society of America shows that rising sea levels of as little as a half-meter per century have been sufficient to dramatically change the shoreline of the U.S. Gulf Coast within the past 10,000 years. The findings are significant because half-meter increases are within the moderate range of predictions for the Gulf Coast during this century.

"About 5,000 years ago, when sea level was rising approximately 50 centimeters per century, the upper part of Corpus Christi Bay increased by about one third over the span of about 200 years," said John Anderson, the W. Maurice Ewing Chair in Oceanography and professor of Earth science at Rice University in Houston. "Even without factoring in any effects from global warming, that's only about 20 percent slower than the projected sea level increases along the Texas and Louisiana coasts this century." [continued]
http://www.eurekalert.org/pub_releases/2004-11/ru-lap110804.php
 
Earth sciences news on Phys.org
Ivan Seeking,

related news:
http://www.reuters.com/newsArticle.jhtml?type=scienceNews&storyID=6760398

While random "bytes" come in supporting the opposition (of GlobWarm reality), the accumulation of evidence is overwhelming.

Temperature is only secondary in the sequence. Water salinity is the "gear" in the system. Ice melting = fresh water IN, and salt content down. This will disturb the oceans' currents, and stop the warm water from moving "up" north. Nature's balance mechanism then must "make new Ice" to correct. Only equatorial regions will be able to produce food during Ice-times.

too late

TRoc
 
Last edited by a moderator:
http://meteo.lcd.lu/globalwarming/McLean/Disputed_Science_of_Global_Warming.pdf

Sea-levels are rising though, and threaten many islands?
They are probably rising by fractions of a millimetre per year. Researchers have found that sea levels are almost unchanged around the world. The IPCC report of 2001 contained a graph showing very small changes in sea levels at 3 locations over a period of two hundred years (see reference 5.1). The same IPCC presented graphs showing rising temperature between 1900 and 1940 but no correlation could be made against change sin sea levels. In Australia, the National Tidal Facility produced a report into its 1998 study of sea level changes. That report stated "The results demonstrate that the overall average of the relative sea level trends is +0.3 mm per year, somewhat less than the IPCC estimated global average of 1-2 mm per year (IPCC, 1995)" (see reference 5.2).

In other instances of sea levels not rising in accordanec with the IPCC's predictions, a groove cut into rock in Tasmania in 1840 to indicate average sea level is now above the water level (see reference 5.3) and sea levels around the Maldives are falling and not rising as some people have claimed (see references 5.4 and 5.5).

As a general rule caution must be used in regard to any claim about changing sea levels because geologists report that land masses are shifting very very slightly, some tilting and others rising or falling. Rather than the sea level rising, it may be that the land is sinking.

cont..
 
Who is John McLean?
 
I doubt if it is important who the copy-paster is. Perhaps check the refs. There are the guys whose credentials do matter.
 
I did start doing that already; some of the linked material is useful. Some of it is more difficult to judge. All of it takes time.

There are parts of his introduction that are not referenced. That information is probably just common knowledge in the field. I was curious to find out what he does and what he studies.

It appears he works in a UV measuring facility in Luxenburg. Any idea if that is correct?

Edited because when I get wordy I sound obnoxious.
 
Last edited:
me too...
 
OK Sorry for seeming a bit harsh too. Too bad words do not convey body language and :smile: or :wink: could have helped. The question could have been interpreted as

"and who the h... does JML think he is, knowing it all better than all those scientists who have consensus ...etc...etc"

And to be honest there are a few shortcuts and inaccuracies in his story.
 
There is no inaccuracy in the story of Louisiana. They are loosing swamp land (retreating shore line) at a terrible rate because they put levies on the Mississippi river and the mud can no longer escape into the swamp. If the sea level rises another meter that will be the end of New Orleans.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 2 ·
Replies
2
Views
8K
  • · Replies 11 ·
Replies
11
Views
7K
Replies
1
Views
2K
Replies
2
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
19K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
39
Views
14K
  • · Replies 73 ·
3
Replies
73
Views
18K
Replies
31
Views
19K